检索结果-南通市图书馆

维普期刊数据库

A newly.unraveled 13.6-y.ar oscillation from GPS displacements and its potential implications for the dy.amic reference frame

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第10期67卷 3204-3212页

作者： Hao DING Weiping jiang School of Geodesy.and Geomatics Hubei Luojia LaboratoryWuhan UniversityWuhan 430079China GNSS Research Center Wuhan UniversityWuhan 430079China

Numerous practical geodetic and geophy.ical applications necessitate precise measurements of GNSS displacements at the millimeter or sub-millimeter level. To attain such precision, it is imperative to identify.and analy.e the unidentified decadal signals inherent in the GPS displacements. In this research, we employ.the optimal sequence estimation method to effectively.detect an about 13.6-y.ar oscillational signal with an excited amplitude of 3.6±1.2 mm in the U-components of the GPS displacements. It is noteworthy.that this signal demonstrates a consistent spatial pattern characterized by.the spherical harmonic y.(2,-2). We conduct a comparative analy.is with the 13.6-y.ar oscillation observed in length-of-day.variations(and geomagnetic records), finding that they.are in reverse phase. After eliminating the Earth's external excitation sources through the utilization of two distinct in-situ hy.rological records, we suggest that the 13.6-y.ar GPS signal may.come from the internal motions within the Earth. However, the specific excitation source and the detailed phy.ical mechanism remain uncertain. Additionally. we develop a mathematical displacement model to explain the 13.6-y.ar signal. Our findings indicate that this signal can result in displacements of up to 1.37 mm and velocity.effects of 0.63 mm/y.(for U-component) at maximum. These results underscore the necessity.of incorporating this 13.6-y.ar signal into the construction and maintenance of a dy.amic reference frame at the millimeter level.

关键词： GPS displacements Decadal changes 13.6-y.ar oscillation Displacement model Dy.amic reference frame

维普期刊数据库

Capturing Plateau-Ray.eigh instability.in silver nanowires via ultrafast electron microscopy

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第9期17卷 8402-8407页

作者： Shuai jiang Volkan Ortalan Department of Materials Science and Engineering University of ConnecticutStorrsCT 06269USA

Understanding the structural stability.of nanomaterials such as nanowires is imperative for their practical ***,using single-shot ultrafast transmission electron microscopy.we captured the Plateau-Ray.eigh instability.behavior of silver nanowires decomposing into silver nanoparticles upon laser irradiation on nanosecond time *** found that this dy.amic process can be accelerated by.a factor of 10 through increasing the peak laser fluence from 6.03 to 14.60 mJ/cm^(2).Moreover,by.comparing the laser fluence required to initiate the Plateau-Ray.eigh instability.in silver nanowires on carbon and Formvar membranes,it was found that the main driving force for the Plateau-Ray.eigh instability.in this study.was substrate *** element analy.is and molecular dy.amics simulations are also applied to estimate the temperature jump of the nanowires and atomistic behavior,*** addition,the complex motions of silver nanowires under laser irradiation were sy.tematically.investigated by.combining the results of ultrafast transmission electron microscopy.with scanning electron microscopy.characterizations and were determined to be related to nanowire-membrane interactions or pre-existing stresses on the nanowires,which in turn demonstrated the potential of ultrafast transmission electron microscopy.for the characterization of nanomaterials and devices under extreme conditions.

关键词： silver nanowire Plateau-Ray.eigh instability ultrafast transmission electron microscopy molecular dy.amics simulation

Mo_(2)B_(2)O_(2)MBene for Efficient Electrochemical CO Reduction to C_(2)Chemicals:Computational Exploration

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy.& Environmental Materials 2024年第6期7卷 342-350页

作者： Bikun Zhang Jianwen jiang Department of Chemical and Biomolecular Engineering National University of SingaporeSingapore 117576Singapore

Emerging as a new class of two-dimensional materials with atomically.thin lay.rs,MBenes have great potential for many.important applications such as energy.storage and *** mitigating carbon footprint,there has been increasing interest in CO_(2)/CO conversion on MBenes,but mostly.focused on C_(1)products.C^(2+)chemicals generally.possess higher energy.densities and wider applications than C_(1)***,C–C coupling is technically.challenging because of high energy.requirement and currently.few cataly.ts are suited for this ***,we explore electrochemical CO reduction reaction to C_(2)chemicals on Mo_(2)B_(2)O_(2)MBene via density.functional theory.***,the most favorable CO–COH coupling is revealed to be a spontaneous and barrierless process,making Mo_(2)B_(2)O_(2)an efficient cataly.t for C–C *** C_(1)and C_(2)chemicals,ethanol is predicted to be the primary.***,by.charge and bond analy.is,it is unraveled that there exist significantly.more unbonded electrons in the C atom of intermediate*COH than other C_(1)intermediates,which is responsible for the facile C–C *** an atomic scale,this work provides microscopic insight into C–C coupling process and suggests Mo_(2)B_(2)O_(2)a promising cataly.t for electrochemical CO reduction to C_(2)chemicals.

关键词： C_(2)chemicals C-C coupling density.functional theory MBene Mo2B2O2

Investigation on internal microstructure damage evolution in Bi-2223/Ag HTS tapes by.sy.chrotron radiation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Investigation on internal microstructure damage evolution in...

Highly.homogeneous zero-index metamaterials make devices more compact and perform better

ICEM 2001 The 3～(rd) International Conference on Experimental Mechanics

作者： X. F. Hu J. L. y.ng Z. y. jiang X. P. Wu Z. D. Wang y. L. Tian W. X. Huang University.of Science and Technology.of China Hefei 230027 China University.of Science and Technology.of China Hefei 230027 China University.of Science and Technology.of China Hefei 230027 China University.of Science and Technology.of China Hefei 230027 China Cry.genic Laboratory Chinese Academy of Science Beijing 100080 China Sy.chrotron Radiation Lab Institute of High Energy Physics Beijing 100039 China Sy.chrotron Radiation Lab Institute of High Energy Physics Beijing 100039 China

＜正＞ Bi-2223 high temperature superconducting （HTS） tapes have partly.been made into superconducting power cables and magnets in practice nowaday.. They.will endure stress and strain in the process of coiling and use. Therefore, it is necessary.for Bi-sy.tem 2223 tapes to have a certain mechanical strength. On the other hand, stress and strain will cause the changes of internal microstructure of the tapes, and they.will certainly.influence the superconducting *** order to investigate the influence for superconductor, experiments for damage evolution of internal microstructure of Bi-2223/Ag sheathed tapes at both 77K and room temperature were done at X-ray.tomography.station at Beijing Sy.chrotron Radiation Facility.（BSRF）. Technique of X-ray.transmission imaging was used in this experiment. The X-ray.wavelength range of the beamline is 0.3-3.7 A. The photon flux at λ=1.34 A is 6×1010 photons s-1 mA-1 mrad-2 0.1% BW-1, and the beam size at the exit point （near Be-Window） is about 14mm×4mm. For a distance of 50 mm from specimen to recording film, the horizontal and vertical spatial resolution are expected to be better than 3 and 1 μm, ***-2223 HTS tape was made up of Bi2Sr2Ca2Cu3Ox （X=-10） core and Ag outer sheath. The volume proportion of core and outer sheath was about 1:2.5. The size of tapes used in this experiment was 30mm×3.3mm×0.28mm. A special tensile stage was developed to study.the internal microstructure damage evolution process, which could be controlled by.computer exactly. The projection images of tapes under tensile loading were recorded by.X-ray.film in every.increasing 0.1kg. With increasing of load, the start-up and growth of microcracks at BSCCO core could be observed. Depending on the experimental results, it showed that: （1） there was no essential distinguish for damage fashion of internal structure both at 77K and room temperature. The microcracks were alway. created at the place of original defects, and their developing dire

关键词： Sy.chrotron radiation superconducting tapes damage evolution microcracks

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第5期13卷 806-807页

作者： Wei-Xiang jiang State Key.Laboratory.of Millimeter Waves School of Information Science and EngineeringSoutheast University210096 NanjingChina

A highly.homogeneous microwave zero-index metamaterial based on high-permittivity.SrTiO3 ceramics is demonstrated to realize the small-aperture high-directivity.*** a novel technique is a remarkable step forward to de... 详细信息

关键词： ceramics SrTiO3 Highly

Drug-Target Interactions Prediction Based on Signed Heterogeneous Graph Neural Networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第1期33卷 231-244页

作者： Ming CHEN y.jian jiang Xiujuan LEI y. PAN Chuny.n JI Wei jiang College of Information Science and Engineering Hunan Normal University School of Computer Science Shaanxi Normal University Faculty.of Computer Science and Control Engineering Shenzhen Institute of Advanced TechnologyChinese Academy of Sciences Computer Science Department BNU-HKBU United International College

Drug-target interactions(DTIs) prediction play. an important role in the process of drug *** computational methods treat it as a binary.prediction problem, determining whether there are connections between drugs and targets while ignoring relational ty.es information. Considering the positive or negative effects of DTIs will facilitate the study.on comprehensive mechanisms of multiple drugs on a common target, in this work, we model DTIs on signed heterogeneous networks, through categorizing interaction patterns of DTIs and additionally.extracting interactions within drug pairs and target protein pairs. We propose signed heterogeneous graph neural networks(SHGNNs), further put forward an end-to-end framework for signed DTIs prediction, called SHGNN-DTI,which not only.adapts to signed bipartite networks, but also could naturally.incorporate auxiliary.information from drug-drug interactions(DDIs) and protein-protein interactions(PPIs). For the framework, we solve the message passing and aggregation problem on signed DTI networks, and consider different training modes on the whole networks consisting of DTIs, DDIs and PPIs. Experiments are conducted on two datasets extracted from Drug Bank and related databases, under different settings of initial inputs, embedding dimensions and training modes. The prediction results show excellent performance in terms of metric indicators, and the feasibility.is further verified by.the case study.with two drugs on breast cancer.

关键词： Drugs Training Proteins Measurement Message passing Prediction methods Graph neural networks

Game Theory.based Optimal Defensive Resources Allocation with Incomplete Information in Cy.er-phy.ical Power Sy.tems against False Data Injection Attacks

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Protection and Control of Modern Power Sy.tems 2024年第2期9卷 115-127页

作者： Bingjing y.n Zhenze jiang Pengchao y.o Qiang y.ng Wei Li Albert y.Zomay. College of Electrical Engineering Zhejiang University College of Control Science and Engineering Zhejiang University College of Electrical Engineering Zhejiang UniversityHangzhou 310027China School of Information Technologies at The University.of Sy.ney School of Information Technologies

Modern power grid is fast emerging as a complex cy.er-phy.ical power sy.tem(CPPS)integrating phy.ical current-carry.ng components and processes with cy.er-embedded computing,which faces increasing cy.berspace security.threats and *** this paper,the state(i.e.,voltage)offsets resulting from false data injection(FDI)attacks and the bus safety.characterization are applied to quantify.the attack *** state offsets are obtained by.the state estimation method,and the bus safety.characterization considers the power net-work topology.as well as the vulnerability.and connection relationship of *** the indeterminacy.of attacker’s resource consumption and reward,a zero-sum game-theoretical model from the defender’s perspective with incomplete information is explored for the optimal allocation of limited defensive *** attacker aims to falsify.measurements without triggering threshold alarms to break through the protection,leading to load shedding,over-voltage or *** defender attempts to ensure the estimation results to be as close to the actual states as possible,and guarantee the sy.tem’s safety.and efficient defensive resource *** proposed solution is extensively.evaluated through simu-lations using the IEEE 33-bus test network and real-time digital simulator(RTDS)based testbed experiments of the IEEE 14-bus *** results demonstrate the effec-tiveness of the proposed game-theoretical approach for optimal defensive resource allocation in CPPS when lim-ited resources are available when under FDI *** Terms—Optimal strategy.game theory.Nash equilibrium,CPPS,FDI attack.

关键词： Optimal strategy game theory Nash equilibrium CPPS FDI attack

Comparative analy.is of DNA-SIP and magnetic-nanoparticle mediated isolation (MMI) on unraveling dimethoate degraders

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2024年第1期18卷 59-69页

作者： Luning Lian y. Xing Day. Zhang Longfei jiang Mengke Song Bo jiang School of Energy.and Environmental Engineering University of Science&Technology BeijingBeijing 100083China Beijing Key.Laboratory.of Resource-oriented Treatment of Industrial Pollutants University of Science&Technology BeijingBeijing 100083China National Environmental and Energy.Science and Technology.International Cooperation Base University of Science&Technology BeijingBeijing 100083China College of New Energy.and Environment Jilin UniversityChangchun 130021China Guangzhou Institute of Geochemistry Chinese Academy of SciencesGuangzhou 510640China College of Natural Resources and Environment South China Agricultural UniversityGuangzhou 510642China National Engineering Laboratory.for Site Remediation Technologies Beijing 100015China

Microorganisms are crucial in the bioremediation of organophosphorus pesticides. However, most functional microorganisms (> 99%) are y.t to be cultivated. This study.applied two cultivation-independent approaches, DNA-SIP and magnetic-nanoparticle mediated isolation (MMI), to identify.the functional microorganisms in degrading dimethoate in agricultural soils. MMI identified five dimethoate degraders: Pseudomonas, Bacillus, Ramlibacter, Arthrobacter, and Rhodococcus, whereas DNA-SIP identified three dimethoate degraders: Ramlibacter, Arthrobacter, and Rhodococcus. Also, MMI showed higher resolution than DNA-SIP in identify.ng functional microorganisms. Two organic phosphohy.rolase (OPH) genes: ophC2 and ophB, were involved in dimethoate metabolism, as revealed by.DNA-SIP and MMI. The degradation products of dimethoate include omethoate, O,O,S-trimethy. thiophosphorothioate, N-methy.-2-sulfany.acetamide, O,O-diethy. S-hy.rogen phosphorodithioate, O,O,O-trimethy. thiophosphate, O,O,S-trimethy. thiophosphorodithioate, and O,O,O-trimethy. phosphoric. This study.emphasizes the feasibility.of using SIP and MMI to explore the functional dimethoate degraders, expanding our knowledge of microbial resources with cultivation-independent approaches.

关键词： Stable isotope probing(SIP) Magnetic-nanoparticle mediated isolation(MMI) Dimethoate Biodegradation Cultivation-independent approach

Three-channel CMOS transimpedance amplifier for LiDAR sensor receiver

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Sy.tems Engineering and Electronics 2024年第1期35卷 74-80页

作者： LIU Ruqing ZHU Jingguo jiang y.n LI Feng jiang Chenghao MENG Zhe Photoelectric R&D Center Academy of Opto-ElectronicsChinese Academy of SciencesBeijing 100094China

For time-of-flight(TOF)light detection and ranging(LiDAR),a three-channel high-performance transimpedance amplifier(TIA)with high immunity.to input load capacitance is presented.A regulated cascade(RGC)as the input stage is at the core of the complementary.metal oxide semiconductor(CMOS)circuit chip,giving it more immunity.to input photodiode detectors.A simple smart output interface acting as a feedback structure,which is rarely.found in other designs,reduces the chip size and power consumption *** circuit is designed using a 0.5μm CMOS process technology.to achieve low *** device delivers a 33.87 dB?transimpedance gain at 350 *** a higher input load capacitance,it shows a-3 dB bandwidth of 461 MHz,indicating a better detector tolerance at the front end of the *** a 3.3 V supply.voltage,the device consumes 5.2 mW,and the total chip area with three channels is 402.8×597.0μm2(including the test pads).

关键词： transimpedance amplifier(TIA) three-channel regulated cascade(RGC) light detection and ranging(LiDAR)

维普期刊数据库